The use of diadynamic therapy - another form of electrical stimulation - varies widely between different countries. It is, for example, relatively rarely used in the UK, whilst in mainland Europe it has a stronger following.
Most people consider it to be consideraably more uncomfortable than other forms of electrical stimulation (like TENS) and this is attributed to the long duration of the 'pulses'.
It is a monophasic pulsed current that was developed in the 1950's, and attributed to Bernard (a French Dentist). The carrier frequency is a sine wave, operating at 50Hz (or 60Hz USA) which is then rectified (full wave or half wave). The resulting monophasic pulses have a duration of 10 msec (milliseconds). In the diagram below, MF is a half wave rectification which will deliver 50 pulses per second, delivering 10ms pulses with a 10ms interval. DF is full wave rectification providing 100 pulses per second, each of which will be the same duration (10ms) but with a zero interpulse interval.
The more complex patterns (CP and LP) are derived from some manipulation of these two basec waveforms.
Given the long pulse duration, uncomfortable nature of the stimulation and minimal specific research, it is difficult to determine the actual advantage over any other kind of electrical stimulation at equivalent pulse frequencies.
The abbreviations used for these different currents relate to the original French terms : MF = monophase fixe : DF = diphase fixe : CP = courtes periodes : LP = longues periodes.
The Can et al (2003) study compared TENS with Diadynamic therapy for a group of patients with patellofemoral pain, showing that both therapies were effective (in terms of pain management) but that there was not significant difference between the two.
Most standard electrotherapy texts cover this therapy in a very superficial way, and a considerable proportion of the literature is not easily available in English - no reason why it should be - but it means that I have difficulty accessing it!!! Some key reference materials are copied below for your information. The original Bernard reference and Belanger book chapter (the most useful one I can find) are at the end of the reference list.
Although Diadynamic based stimulation appears to generate relatively few publication (certainly in English), there is a small but steady trickle. Some of the more recent material is identified below :
Grajić et al (2020) :Compared TENS and Diadynamic stimulation in a trial for patients with acute low back pain (N=60). Pain was the primary outcome but also considered flexibility and muscle tone. Both groups demonstrated significant improvement on all outcomes but there was a significant advantage to those in the TENS group - thus, although both stimulation modes were effective, on comparison, the TENS effects were 'better'.
Demidas and Zarzycki (2019) also compared TENS and Diadynamic - this time in terms of touch and pain sensations (N = 40 healthy participants - so not a clinical study). Both significantly affected touch sensation, pressure pain threshold and pressure pain tolerance threshold, but they were not significantly different in the magnitude of the effects. The authors argue that diadynamic better as treatment times are shorter. I would argue that TENS is better - as the patient can deliver at home and not use up clinic time.
Gomes et al (2018) combines Diadynamic Therapy with Manual therapy looking at the effect on trigger points in patients with shoulder impingement syndrome (N=60). 3 groups - both therapies, manual therapy alone or diadynamic alone; 16 sessions over 8 weeks. The combined group did better than either of the individual therapies - but the results were not marked and pain intensity was the dominant effect.
Ebadi et al (2018) looked at the effect of diadynamic therapy in patients with low back pain, comparing outcomes against TENS (again) in N=30 patients. The TENS group achieved significant pain reduction whilst those in the diadynamic group did not.
Sayilir and Yildizgoren (2017) also compared TENS vs Diadynamic therapies in patients with chronic low back pain (N=55). Patients also received Ultrasound and Hot Pack. Both groups significantly improved - but neither appeared to demonstrate superiority.
Rajfur et al (2017) copmpared multiple modalities in a patient group with chronic low back pain. There were 123 patients dicided across 6 groups : Conventional TENS; Acupuncture mode TENS; HVPC; Interferential; Disdynamic Therapy and Control. Interferential gave the strongest results and in the words of the authors " . . . the use of Diadynamic currents appears to be useless . . . ". [By the way, the TENS and HVPC groups significantly improved - just that the Interferential effects were stronger].
I have another 135 of these . . . but you get the flavour by now . . . . .
Bolel, K., S. Hizmetli, et al. (2006). "Sympathetic skin responses in reflex sympathetic dystrophy." Rheumatol Int 26(9): 788-91.
Can, F., R. Tandoğan, et al. (2003). "Rehabilitation of patellofemoral pain syndrome: TENS versus diadynamic current therapy for pain relief." The Pain Clinic 15(1): 61-68.
de Carvalho, A. R., E. M. Fungueto, et al. (2005). "Bernard's diadynamic currents and iontophoresis in low back pain treatment [Portuguese]." Fisioterapia em Movimento 18(4): 11-9.
Demidas, A.M. Zarzycki (2019) Touch and Pain Sensations in Diadynamic Current (DD) and Transcutaneous Electrical Nerve Stimulation (TENS): A Randomized Study Biomed Res Int 2019: 9073073
Ebadi, S. et al (2018) No immediate analgesic effect of diadynamic current in patients with nonspecific low back pain in comparison to TENS J Bodyw Mov Ther 22(3): 693
Gomes, C. et al (2018) Combined Use of Diadynamic Currents and Manual Therapy on Myofascial Trigger Points in Patients With Shoulder Impingement Syndrome: A Randomized Controlled Trial J Manipulative Physiol Ther 41(6): 475
Grajić, M. et al (2020) Transcutaneous electrical nerve stimulation and diadynamic current therapy in the management of acute low back pain Medicinski pregled 73(11-12): 369
Hamalainen, O. and Kemppainen, P. (1990). Experimentally induced ischaemic pain and so called diaphase fix current. Scand J Rehab Medicine 22; 25-27
Iudel'son Ia, B. and N. P. Gribova (1994). "[The diagnosis and treatment of cervical radiculomyeloischemia]." Zh Nevropatol Psikhiatr Im S S Korsakova 94(2): 55-9.
Iudel'son, I. B. and N. P. Gribova (1994). "[The diagnosis and treatment of cervical radiculomyeloischemia]." Zh Nevropatol Psikhiatr Im S S Korsakova 94(2): 55-9.
Izakson Kh, A. and D. S. Gimmel'farb (1970). "[Experience in the use of diadynamic electrical current in combination with the administration of novocaine by this means in neurologic practice]." Vopr Kurortol Fizioter Lech Fiz Kult 35(4): 361-2.
Kiseleva, S. S. and V. V. Dvurechenskii (2002). "[Experience in using diadynamic currents in patients with acute rhinitis]." Vopr Kurortol Fizioter Lech Fiz Kult(1): 43.
Kroeling, P., A. Gross, et al. (2005). "Electrotherapy for neck disorders." Cochrane Database Syst Rev(2): CD004251.
Kroeling, P., A. R. Gross, et al. (2005). "A Cochrane review of electrotherapy for mechanical neck disorders." Spine 30(21): E641-8.
Rajfur, J. et al (2017) Efficacy of Selected Electrical Therapies on Chronic Low Back Pain: A Comparative Clinical Pilot Study Med Sci Monit 23: 85
Romanenko, S. G., O. P. Tokarev, et al. (2001). "[Electrostimulation of laryngeal muscles with fluctuating currents in the treatment of patients with unilateral laryngeal paralysis]." Vestn Otorinolaringol(3): 52-4.
Sadil, V. and S. Sadil (1994). "[Electrotherapy]." Wien Med Wochenschr 144(20-21): 509-20.
Sayilir, S.M. T. Yildizgoren (2017) The medium-term effects of diadynamic currents in chronic low back pain; TENS versus diadynamic currents: A randomised, follow-up study Complement Ther Clin Pract 29: 16
Theron, E. Vermeulen, A, (1983). The utilisation of transcutaneous nerve stimulation in postoperative ileus. S Af Med J 63;971-972
Tonazzi, A., C. Bertolini, et al. (1981). "[The use of diadynamic currents in minor sports injuries]." Arch Putti Chir Organi Mov 31: 195-205.
Zytkowski, A. (1999). "[Ectodermal method of Ryodorak--an attempt at clinical measurement for evaluation of physiotherapy effects in patients with low back pain]." Neurol Neurochir Pol 32 Suppl 6: 207-15.
Bernard, P. (1950). La therapie diadynamique. Les Editions Naim. Paris
Useful Book Chapters: the most useful book chapter on this topic that I have seen is in: Evidence Based Guide to Therapeutic Physical Agents. Alain-Yvan Belanger.2003. Lippincott Williams Wilkins (details on the BOOK pages)